Copending application Ser. No. 581,085, filed Feb. 17, 1984 and assigned to Photon Devices Ltd., discloses a scanner which employs a fiber optic bundle. The bundle is constrained to a linear geometry at one end for convenience of scanning a document line by line. The opposite end is merely gathered at random into a bundle.
Coherence between the data entering the fibers at the linear end and data exiting the gathered ends of the fibers is produced electronically. Specifically, the gathered ends of the fiber are abutted against a light sensitive array such as a Random Access Memory (RAM) or Charge Coupled Device (CCD). The system is initialized by passing light into consecutive fibers at the linear array end and detecting which fiber the light exits from at the bundled end. The relationship is recorded by storing the RAM or CCD address corresponding to the fiber illuminated. The set of addresses so generated is stored conveniently in a Look-up Table or a Programmable Read Only Memory (PROM) and provides a bit map. The addresses of the bit map are interrogated each time the linear end of the scanner is moved to a next consecutive line of a document until the entire document is scanned.
During each clock cycle, the RAM is interrogated in a manner to detect the presence or absence of light at the sequence of addresses corresponding to the sequence of fibers in the linear array. The data input pattern is read out coherently in accordance with the bit map stored during an initializing procedure. Thus, coherence is obtained electronically rather than by the physical positioning of the fibers at the two ends of the bundle.
But grey scale is not achieved with the arrangements of my above-mentioned patent application without the use of such devices as CCD's which are relatively costly.